Tilted Mobile Goal Idea


I haven’t really read much of the discussion stuff on here but I had this idea the other day. It intakes cones that are down (or could intake upright cones and tilt it passively with a bar or something). Side rollers (or a Skyrise-like cube intake) might work well, but I haven’t really thought about it much. Expanding the base will probably be needed since 18" won’t produce a high enough stack. I’m not too sure about possession and stuff, but I’m pretty sure it’ll be legal. Tilting the mobile goal would probably take 2 motors (unless someone gets creative).

I’m posting this here because I’m not exactly sure how to go about making this design (I might prototype some parts maybe).

Interesting idea, I like it. Here is what I think.


  1. Unique design
  2. Easier to carry larger stacks without fear of tipping
  3. tall lift not needed.


  1. You are rather limited in the amount of cones you can hold, (only as many that you can expand your base too. For example, its about 3 feet for 10 cones on the mobile base, which means you’d have to expand your base by double. Not saying there isn’t a way, but just pointing out the challenge.

  2. Balance overall is going to get weird. The mobile goal is extremely bottom heavy, and you’ll have a lot of difficulty keeping it in the position you need it in (without just locking it in place).

  3. You risk dropping the entire stack when you unload the mobile goal. This all depends on the implementation of your design though, a good mechanism eliminates this problem.

  4. Probably needs torque drive

If you can overcome these it might work. One way to do this is to have a set of rack gears on a slider rail, then push them in and out with a pinion. On the end of the rack, will be your intake design.

The torque required is greatly offset by the lack of motors needed for a DR4B and claw. I had a similar idea earlier and never thought of using side rollers. The biggest problem I see is righting the goal back up in the 5, 10, or hopefully 20 point zone. I would absolutely love to use this design if I could think of some way to right the goal effectively.

I was going to make a bot very similar to this and i had it planned out and was prototyping when i found this thread about perspective of stacks and Karthik said cones don’t count as stacked sideways.

The question I had with a design like this would be how to deal with cones from the loader?

The real question is if it has to be completely upright in order to count as stacked… the side rolled could just lift up the cone a bit on a sloped plain or something…

Pretty sure this is illegal, since stacks that are laying on their side are no longer a stack and therefore you would be in possession of all cones on the robot, therefore exceeding the possession limit.


According to this response, the cones would not be scored as stacked.


According to this, it might be that although it does not count as stacked, it may be legal in terms of possession. I would be interested in hearing an official ruling on this.

I don’t think it would be legal in terms of possession either. The definition of possession:
Possessing – A Robot is considered to be Possessing a Cone if it is carrying, holding, or controlling the movement of a Cone in the Robot. Pushing/plowing Cones is not considered Possession, however using concave portions of your Robot to control the movement of Cones is considered Possession.
and the rule regarding possession:
<SG9> Robots may not Possess more than one (1) Cone at a time.

Therefore, since cones nested on a horizontal mobile goal are not considered “stacked”, the they would still count as possessed and a robot is not allowed to “possess” more than one cone at a time.

But what if it weren’t horizontal? Rather, what if it were slanted down so that the cones would be above the mobile goal? I know bracing v. incidental touching hasn’t be clarified yet. But if bracing is allowed, I would think a slight angle above horizontal would qualify as bracing and make this design legal.

I don’t think this idea makes any sense. I’ve already built a fast DR4B for stacking cones that only takes two motors. The plus side is that it is more maneuverable (I don’t have a giant stack of cones behind me, or in front of me, whatever), and I don’t need a mechanism to put the mobile goal upright. Then of course, this idea is probably not legal for previously-mentioned reasons, so there’s that.

It just takes too much effort. You have to add the extra steps of acquiring the mobile goal and knocking all the cones over. Plus, the cones can roll so they would be harder to pick up and stack.

This would be amazing consider the clarification of the robot “touching” more then one cone!!

I would like to see @Karthik give a ruling on the legality, first, and if it is legal, i would love to see a team run with this idea. I am hoping to see something besides a DR4B win either Tournament Champion or Excellence Award this year at worlds. That would make it a good year.

The rulings Karthik has made already plus the reading of the definition of possession and <SG9>, in my opinion, make the OPs approach illegal. I am pretty certain that Karthik will concur. An official ruling would still not be a bad thing. however.


I would consider this ruling to at the very least open the door to a distinction between “Stacked” in a scoring sense, and stacked in a mechanical sense. The way i read this ruling, it is intended that the robot may touch the stacked cones, on a mobile goal, for purposes of stability. If it ends the match holding them up, they are not scored as “Stacked”, but they do not violate the possession limit.

In the tipped goal method, it has been ruled here:


That the cones would not be counted as “Stacked”, but i could easily see the allowance of contact in the same principle of stabilizing a stack of cones on a mobile goal before the final score, without it violating possession limits.

This certainly does not equate to a ruling of legality, but to me, it certainly leaves it open until their is an official ruling.

Point taken!